Fast FOUP swapping with a FOUP handler

ABSTRACT

A vertical batch furnace assembly for processing wafers having a cassette handling space, a wafer handling space, and a first wall and separating the cassette handling space from the wafer handling space. The first wall has at least one wafer transfer opening in front of which, at a side of the first wall which is directed to the cassette handling space, a wafer transfer position for a wafer cassette is provided. The cassette handling space comprises a cassette storage having a plurality of cassette storage positions and a cassette handler configured to transfer wafer cassettes between the cassette storage positions and the wafer transfer position. The cassette handler has a first cassette handler arm and a second cassette handler arm.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to U.S. Provisional Patent Application Ser. No. 63/018,810 filed May 1, 2020 titled FAST FOUP SWAPPING WITH A FOUP HANDLER, the disclosure of which is hereby incorporated by reference in its entirety.

FIELD OF THE DISCLOSURE

The present disclosure generally relates to a vertical batch furnace assembly comprising a cassette handler.

BACKGROUND

Vertical batch furnace assemblies for processing wafers comprise a cassette handling space, a wafer handling space, and a wall separating these two spaces. The wall has a wafer transfer opening provided with a cassette door opener device in front of which a wafer transfer position for a wafer cassette is provided. The cassette handling space is provided with cassette handler which may transport wafer cassettes between the wafer transfer position and a cassette storage in which the wafer cassettes may be stored. The wafer handling space of the vertical batch furnace assembly may also be provided with a wafer handler which may remove wafers from a wafer cassette which is in the wafer transfer position, and transfer those wafers through the wafer transfer opening to a wafer boat for applying a treatment in a process chamber. After treatment of said wafers the wafer handler may also put the wafers back into the wafer cassette which is in the wafer transfer position. Subsequently, the cassette handler may transfer the wafer cassette to the cassette storage and replace it with another wafer cassette from the cassette storage.

SUMMARY

This summary is provided to introduce a selection of concepts in a simplified form. These concepts are described in further detail in the detailed description of example embodiments of the disclosure below. This summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter.

It may be realized that typically multiple wafer cassettes need to be unloaded to fill an entire wafer boat and that during the transfer of wafer cassettes to and from the wafer transfer position, the wafer handler may be unable to transfer wafers and remains idle. Also, during transfer by the wafer handler of wafers to and/from the cassette which is in the wafer transfer position, the cassette hander may be unable to transport a wafer cassette to or from the wafer transfer position and remains idle. These idle times may be detrimental to the efficiency of the vertical batch furnace assembly.

Therefore, it may be an object to provide a vertical batch furnace assembly with improved capacity.

To that end, there may be provided a vertical batch furnace assembly according to claim 1. More particularly, there may be provided a vertical batch furnace assembly for processing wafers. The vertical batch furnace assembly may comprise a cassette handling space, a wafer handling space, and a first wall separating the cassette handling space from the wafer handling space. The first wall may have at least one wafer transfer opening in front of which, at a side of the first wall which is directed to the cassette handling space, a wafer transfer position for a wafer cassette is provided. The cassette handling space may comprise a cassette storage and a cassette handler. The cassette storage may have a plurality of cassette storage positions each configured to store a wafer cassette provided with a plurality of wafers. The cassette handler may be configured to transfer wafer cassettes between the cassette storage positions and the wafer transfer position. The cassette handler may comprise a first cassette handler arm, and a second cassette handler arm.

For purposes of summarizing the invention and the advantages achieved over the prior art, certain objects and advantages of the invention have been described herein above. Of course, it is to be understood that not necessarily all such objects or advantages may be achieved in accordance with any particular embodiment of the invention. Thus, for example, those skilled in the art will recognize that the invention may be embodied or carried out in a manner that achieves or optimizes one advantage or group of advantages as taught or suggested herein without necessarily achieving other objects or advantages as may be taught or suggested herein.

Various embodiments are claimed in the dependent claims, which will be further elucidated with reference to examples shown in the figures. The embodiments may be combined or may be applied separate from each other.

All of these embodiments are intended to be within the scope of the invention herein disclosed. These and other embodiments will become readily apparent to those skilled in the art from the following detailed description of certain embodiments having reference to the attached figures, the invention not being limited to any particular embodiment(s) disclosed.

BRIEF DESCRIPTION OF THE FIGURES

While the specification concludes with claims particularly pointing out and distinctly claiming what are regarded as embodiments of the invention, the advantages of embodiments of the disclosure may be more readily ascertained from the description of certain examples of the embodiments of the disclosure when read in conjunction with the accompanying drawings, in which:

FIG. 1 shows an example of the relevant part of the vertical batch furnace assembly according to the description;

FIG. 2 shows an example of a cassette handler arm according to the description;

FIG. 3 shows the example of FIG. 1 wherein the cassette handler arms have transferred the cassettes;

FIG. 4 schematically shows another example of the vertical batch furnace assembly according to the description.

DETAILED DESCRIPTION OF THE FIGURES

In this application similar or corresponding features are denoted by similar or corresponding reference signs. The description of the various embodiments is not limited to the example shown in the figures and the reference numbers used in the detailed description and the claims are not intended to limit the description of the embodiments, but are included to elucidate the embodiments.

Although certain embodiments and examples are disclosed below, it will be understood by those in the art that the invention extends beyond the specifically disclosed embodiments and/or uses of the invention and obvious modifications and equivalents thereof. Thus, it is intended that the scope of the invention disclosed should not be limited by the particular disclosed embodiments described below. The illustrations presented herein are not meant to be actual views of any particular material, structure, or device, but are merely idealized representations that are used to describe embodiments of the disclosure.

As used herein, the term “wafer” may refer to any underlying material or materials that may be used, or upon which, a device, a circuit, or a film may be formed.

In the most general term the present disclosure may provide a vertical batch furnace assembly 10 for processing wafers. An example of the relevant part of the vertical batch furnace assembly 10 is shown in FIGS. 1, 3 and 4 to which reference is made in the following but which are non-limiting examples. The vertical batch furnace assembly 10 may comprise a cassette handling space 12, a wafer handling space 14, and a first wall 16 separating the cassette handling space 12 from the wafer handling space 14. The first wall 16 may have at least one wafer transfer opening 20 in front of which, at a side of the first wall 16 which is directed to the cassette handling space 12, a wafer transfer position 22 for a wafer cassette 60 is provided. The cassette handling space 12 may comprise a cassette storage and a cassette handler 26, 28, 30. The cassette storage may have a plurality of cassette storage positions 24 each configured to store a wafer cassette 60 provided with a plurality of wafers. The cassette handler 26, 28, 30 may be configured to transfer wafer cassettes 60 between the cassette storage positions 24 and the wafer transfer position 22. The cassette handler 26, 28, 30 may comprise a first cassette handler arm 28, and a second cassette handler arm 30. In an embodiment, the cassette handler 26, 28, 30 may further comprise an elevator mechanism configured to reach wafer cassettes placed on cassette storage positions at different vertical levels within the cassette handling space.

When a first wafer cassette 60 is in the wafer transfer position 22, a wafer handler (not shown) may load/unload wafers in/from the first wafer cassette 60, e.g. to transfer the wafers to a wafer boat in which the wafers may be mounted during a treatment in a process chamber of the vertical batch furnace. With the vertical batch furnace assembly 10 according the description comprising the cassette handler 26, 28, 30 having a first and a second cassette handler arm 28, 30, the cassette handler 26, 28, 30 may already get a second wafer cassette 60 from the cassette storage and transfer it to location near the wafer transfer position 22, while the wafer handler is loading/unloading the wafers from the first wafer cassette 60. The cassette handler 26, 28, 30 may use one of the first and second cassette handler arms 28, 30 to hold the second wafer cassette 60, while the other one of the cassette handler arm 28, 30 is free. As soon as the wafer handler is ready with the loading/unloading of the first wafer cassette 60, the cassette handler 26, 28, 30 may remove the first wafer cassette 60 from the wafer transfer position 22 with the free cassette handler arm 28, 30, and immediately afterwards place the second wafer cassette 60 in the wafer transfer position 22 with the other cassette handler arm 28, 30. The cassette handler 26, 28, 30 does not have to transfer the first wafer cassette 60 all the way to a cassette storage position 24 and transfer the second wafer cassette 60 all the way from another cassette storage position 24 to the wafer transfer position 22, thus reducing the transfer path and thereby saving time in which the wafer handler would otherwise remain idle.

In an embodiment the cassette handler 26, 28, 30 may further comprise a movable carriage 26 which is movable in a first direction 32. Both the first cassette handler arm 28 and the second cassette handler arm 30 may each with a respective first end be connected to the movable carriage 26.

Due to the fact that a single carriage 26 may carry both cassette handler arms 28, 30, only a single drive may be needed to transport both arms along the first direction.

In an embodiment, the first cassette handler arm 28 and the second cassette handler arm 30 may each have a respective second end, wherein each respective arm 28, 30 may be configured to move its second end away from and towards its first end.

Such an embodiment enable the cassette handler arms 28, 30 to reach extend and retract.

In a further elaboration, both the first and second cassette handler arms 28, 30 at or near a first end thereof may be pivotably connected to the movable carriage 26 of the cassette handler 26, 28, 30. The respective cassette handler arm 28, 30 at or near the second end thereof may comprise a cassette gripper 34 configured to grip a wafer cassette 60. The cassette gripper 34 of the first cassette handler arm 28 may be pivotably connected to the first cassette handler arm 28. The cassette gripper 34 of the second cassette handler arm 30 may be pivotably connected to the second cassette handler arm 30.

The movable carriage 26 provides a base for movement of the two cassette handler arms 28, 30 simultaneously. When attached to the movable carriage 26, both arms 28, 30 may move together with the movable carriage 26. In this way both arms may be near the wafer transfer position 22 or both may be near a cassette storage position 24.

In an embodiment, the first direction may be substantially vertical and the cassette handler 26, 28, 30 may further comprise an elevator mechanism which may be configured to transfer the movable carriage 26 upwardly and downwardly so that the first and second cassette handler arms 28, 30 are able reach wafer cassettes placed on cassette storage position at different vertical levels within the cassette handling space.

In such this embodiment, movement in a plane perpendicular to the first direction 32 may be done by the cassette handler arms 28, 30 themselves which may, for example, be pivotably connected to the movable carriage 26. Alternatively, a guide 36 on which the movable carriage 26 may be mounted for movement along the first direction may be rotatable around an axis extending in the first direction. It is also possible that the movable carriage 26 is rotatable around a guide 36 along an axis extending in the first direction. That same guide 36 may also serve as the guide 36 for movement of the movable carriage 26 along the first direction.

In an embodiment, the elevator mechanism 36, 38, 40 may comprise at least one first direction guide 36, 38 extending in the first direction 32. The movable carriage 26 may be moveably mounted on the at least one first direction guide 36, 38 and may be moveable along the first direction 32. The at least one first direction guide 36, 38 thus provides the movement of the movable carriage 26 in the first direction 32.

In an embodiment, of which an example is shown in FIGS. 1 and 3, the movable carriage 26 may be additionally movable in a second direction 42, perpendicular to the first direction 32. To that end, the elevator mechanism 36, 38, 40 may comprise at least one first direction guide 36, 38 extending in the first direction 32 and a transverse guide 40 extending in the second direction 42. The movable carriage 26 may be moveably mounted on the transverse guide 40 and may be moveable along the second direction 42. Transverse guide 40 may be movably mounted on the at least one first direction guide 36, 38 and may be moveable along the first direction 32. The at least one first direction guide 36, 38 may comprise a first guide 36 and a second guide 38. The transverse guide 40 may be mounted between said first guide 36 and said second guide 38. The at least one first direction guide 36, 38, and the transverse guide 40 thus together provide the movement along the first direction 32 and along the second direction 42. Such a configuration is extremely stable and the carriage 26 may be moved at relatively high speed in a plane of movement which is parallel to the first and second directions.

In an embodiment, in which the carriage 26 is only moveable along the first direction, of which an example is shown in FIG. 4, the cassette storage positions 24 may be located at equal distances from a line of movement 62 along which the movable carriage 26 is moveable in the first direction. The wafer transfer position 22 may be positioned at substantially the same distance from the line of movement 62 as the cassette storage positions 24. In such a configuration, the cassette storage positions 24 may be positioned in circles or circle segments around the line of movement 62 at different vertical levels.

In another embodiment, in which the carriage 26 is moveable along the first direction and the second direction which are perpendicular to each other, of which examples are shown in the FIGS. 1 and 3, the cassette storage positions 24 may located at equal distances from a plane 44 of movement of the movable carriage 26. The plane 44 may be parallel to the first and the second directions. The cassette storage position 24 may be at a first side of the plane 44 and/or at a second side of the plane 44 opposite the first side. The wafer transfer position 22 may be positioned at either the first or the second side of the plane 44 at substantially the same distance of the plane 44 as the cassette storage position 24.

Due to the fact that, in this embodiment, the cassette storage positions 24 and the wafer transfer position 22 may be at equal distances from the plane 44, the cassette handler arms 28, 30 thus only need to have one range of movement to be able to reach all the cassette storage positions 24 and the wafer transfer position 22. This means that a simpler design for these arms may suffice. For example, a design with three pivot points may suffice for the cassette handler arms 28, 30. Thus, the cassette handler arms 28, 30 and the control thereof may be relatively simple.

In an embodiment, of which an example is shown in FIG. 2, both the first cassette handler arm 28 and the second cassette handler arm 30 may comprise a first and a second arm parts 46, 48 and a pivot joint 50 pivotably connecting said first and second arm parts 46, 48. The first arm part 46 may be pivotably connected to the movable carriage 26 along a pivot joint 64. The second arm part 48 may be pivotable connected to the cassette gripper 34 along a pivot joint 66. In this way both cassette handler arms 28, 30 may pivot around their joints 64, 50 and 66 thereby reducing or increasing the distance between end parts of the respective cassette handler arms 28, 30. Thus, a gripped wafer cassette 60 may be moved towards or away from the moveable carriage 26. The wafer cassette 60 may be moved away from the moveable carriage 26 to pick/place said wafer cassette 60 in/from the wafer transfer position 22, or on/from a cassette storage position 24. The gripper 34 with the wafer cassette 60 may be moved towards the moveable carriage 26 when transferring of the movable carriage 26 along the first and optionally the second direction 32, 42 is desired.

In an embodiment, the wafer cassettes 60 may be embodied as Front Opening Unified Pods (FOUP's). FOUP's are standardized wafer cassettes 60 for wafers in the industry. Using FOUP's is advantageous for exchangeability of the wafer cassettes 60 between the vertical batch furnace assembly 10 and other wafer processing machines.

In an embodiment, of which an example is shown in FIGS. 1 and 3, the first cassette handler arm 28 and the second cassette handler 30 arm may be arranged horizontally next to each other.

In an alternative embodiment, of which an example is shown in FIG. 4, the first cassette handler arm 28 and the second cassette handler arm 30 may be arranged vertically above each other. It may also be possible to arrange the first cassette handler arm 28 and the second cassette handler 30 arm neither horizontally next to each other, nor vertically above each other, but in an other orientation with respect to each other, e.g. diagonally above each other. Which configuration is best for a certain vertical bath furnace assembly may depend on the configuration of the cassette handling space 12.

In an embodiment, the vertical batch furnace assembly 10 may further comprise at least one cassette in-out port 52 provided in a wall 16, 18 bounding the cassette handling space 12. The cassette handler 26, 28, 30 may be configured to additionally transfer wafer cassettes 60 to and from the at least one cassette in-out port 52. The at least one cassette in-out-port 52 may be provided in a second wall 18 bounding the cassette handling space 12, opposite the first wall 16.

The at least one cassette in-out port 52 may provide the entrance to and the exit from the vertical batch furnace assembly 10, for the exchange of wafer cassettes 60 between the vertical batch furnace assembly 10 and the outside world, in particular the clean room environment.

In an embodiment, the vertical batch furnace assembly 10 may comprise a cassette door opener device 54 for each wafer transfer opening 20. The cassette door opener device 54 may be configured to open a cassette door of a wafer cassette 60 which has been placed in the wafer transfer position 22.

In an embodiment, the vertical batch furnace assembly 10 may further comprise a wafer handler, a process chamber, and a wafer boat handling device. The wafer handler may be positioned in the wafer handling space 14 and may be configured to transfer wafers between a wafer cassette 60 in the wafer transfer position 22 and a wafer boat. The process chamber may be configured to process wafers accommodated in the wafer boat. The wafer boat handling device may be positioned under the process chamber and adjacent the wafer handling space 14. The wafer boat handling device may be provided with the wafer boat in a wafer boat transfer position, and may be configured to transport the wafer boat between the wafer boat transfer position and the process chamber.

Although illustrative embodiments of the present invention have been described above, in part with reference to the accompanying drawings, it is to be understood that the invention is not limited to these embodiments. Variations to the disclosed embodiments can be understood and effected by those skilled in the art in practicing the claimed invention, from a study of the drawings, the disclosure, and the appended claims.

Reference throughout this specification to “one embodiment” or “an embodiment” means that a particular feature, structure or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, the appearances of the phrases “in one embodiment” or “in an embodiment” in various places throughout this description are not necessarily all referring to the same embodiment.

Furthermore, it is noted that particular features, structures, or characteristics of one or more of the various embodiments which are described above may be used implemented independently from one another and may be combined in any suitable manner to form new, not explicitly described embodiments. The reference numbers used in the detailed description and the claims do not limit the description of the embodiments, nor do they limit the claims. The reference numbers are solely used to clarify.

LEGEND

-   10—vertical batch furnace assembly -   12—cassette handling space -   14—wafer handling space -   16—first wall -   18—second wall -   20—wafer transfer opening -   22—wafer transfer position -   24—cassette storage position -   26—movable carriage -   28—first cassette handler arm -   30—second cassette handler arm -   32—first direction -   34—cassette gripper -   36—first guide -   38—second guide -   40—transverse guide -   42—second direction -   44—plane -   46—first arm part -   48—second arm part -   50—joint -   52—cassette in-out port -   54—cassette door opener device -   60—wafer cassette -   62—line of movement -   64—pivot joint -   66—pivot joint 

The invention claimed is:
 1. A vertical batch furnace assembly for processing wafers comprising: a cassette handling space; a wafer handling space; and a first wall and separating the cassette handling space from the wafer handling space and having at least one wafer transfer opening in front of which, at a side of the first wall which is directed to the cassette handling space, a wafer transfer position for a wafer cassette is provided; wherein the cassette handling space comprises: a cassette storage having a plurality of cassette storage positions each configured to store a wafer cassette provided with a plurality of wafers; and a cassette handler configured to transfer wafer cassettes between the cassette storage positions and the wafer transfer position, wherein the cassette handler comprises: a first cassette handler arm; a second cassette handler arm; a movable carriage which is movable in a first direction, wherein both the first cassette handler arm and the second cassette handler arm are each with a respective first end connected to the movable carriage, wherein the first direction is substantially vertical; and an elevator mechanism configured to transfer the movable carriage upwardly and downwardly so that the first and second cassette handler arms are able to reach wafer cassettes placed on cassette storage positions at different vertical levels within the cassette handling space, wherein the elevator mechanism comprises at least one first direction guide extending in the first direction and a transverse guide extending in the second direction, wherein the movable carriage is moveably mounted on the transverse guide and is moveable along the second direction, wherein the transverse guide is movably mounted on the at least one first direction guide and is moveable along the first direction, and wherein the at least one first direction guide comprises a first guide and a second guide, wherein the transverse guide is mounted between said first guide and said second guide.
 2. The vertical batch furnace assembly according to claim 1, wherein the first cassette handler arm and the second cassette handler arm each have a respective second end, wherein each respective arm is configured to move its second end away from and towards its first end.
 3. The vertical batch furnace assembly according claim 2, wherein both the first and second cassette handler arms at or near the first end thereof are pivotably connected to the movable carriage of the cassette handler, and wherein the respective cassette handler arm at or near a second end thereof comprises a cassette gripper configured to grip a wafer cassette.
 4. The vertical batch furnace assembly according to claim 3, wherein the cassette gripper of the first cassette handler arm is pivotably connected to the first cassette handler arm, and wherein the cassette gripper of the second cassette handler arm is pivotably connected to the second cassette handler arm.
 5. The vertical batch furnace assembly according to claim 1, wherein the elevator mechanism comprises at least one first direction guide extending in the first direction, wherein the movable carriage is moveably mounted on the at least one first direction guide and is moveable along the first direction.
 6. The vertical batch furnace assembly according to claim 1, wherein the second direction is perpendicular to the first direction.
 7. The vertical batch furnace assembly according to claim 1, wherein the cassette storage positions are located at equal distances from a line of movement along which the movable carriage is moveable in the first direction, wherein the wafer transfer position is positioned at substantially the same distance from the line of movement as the cassette storage positions.
 8. The vertical batch furnace assembly according to claim 6, wherein the cassette storage positions are located at equal distances from a plane of movement of the movable carriage which plane is parallel to the first and the second directions, wherein the cassette storage position are at a first side of the plane and/or at a second side of the plane opposite the first side, wherein the wafer transfer position is positioned at either the first or the second side of the plane at substantially the same distance of the plane as the cassette storage position.
 9. The vertical batch furnace assembly according to claim 1, wherein both the first cassette handler arm and the second cassette handler arm comprise a first and a second arm part and a pivot joint pivotably connecting said first and second arm parts wherein the first arm part is pivotably connected to the movable carriage along a pivot joint, and wherein the second arm part is pivotably connected to a cassette gripper along a pivot joint.
 10. The vertical batch furnace assembly according to claim 1, wherein the wafer cassettes are embodied as Front Opening Unified Pods (FOUP's).
 11. The vertical batch furnace assembly according to claim 1, wherein the first cassette handler arm and the second cassette handler arm are arranged vertically next to each other.
 12. A vertical batch furnace assembly for processing wafers comprising: a cassette handling space; a wafer handling space; and a first wall and separating the cassette handling space from the wafer handling space and having at least one wafer transfer opening in front of which, at a side of the first wall which is directed to the cassette handling space, a wafer transfer position for a wafer cassette is provided; wherein the cassette handling space comprises: a cassette storage having a plurality of cassette storage positions each configured to store a wafer cassette provided with a plurality of wafers; and a cassette handler configured to transfer wafer cassettes between the cassette storage positions and the wafer transfer position, wherein the cassette handler comprises: a first cassette handler arm; a second cassette handler arm, wherein the first cassette handler arm and the second cassette handler arm are arranged vertically above each other.
 13. The vertical batch furnace assembly according to claim 1, further comprising at least one cassette in-out port provided in a wall bounding the cassette handling space, wherein the cassette handler is configured to additionally transfer wafer cassettes to and from the at least one cassette in-out port.
 14. The vertical batch furnace assembly according to claim 13, wherein the at least one cassette in-out-port is provided in a second wall bounding the cassette handling space, opposite the first wall.
 15. The vertical batch furnace assembly according to claim 1 wherein for each wafer transfer opening the vertical batch furnace assembly comprises: a cassette door opener device configured to open a cassette door of a wafer cassette which has been placed in the wafer transfer position.
 16. The vertical batch furnace assembly according to claim 1, wherein the vertical batch furnace assembly further comprises: a wafer handler positioned in the wafer handling space and configured to transfer wafers between a wafer cassette in the wafer transfer position and a wafer boat; a process chamber configured to process wafers accommodated in the wafer boat; and a wafer boat handling device positioned under the process chamber and adjacent the wafer handling space, wherein the wafer boat handling device is provided with the wafer boat in a wafer boat transfer position, and is configured to transport the wafer boat between the wafer boat transfer position and the process chamber.
 17. The vertical batch furnace assembly according to claim 12, further comprising at least one cassette in-out port provided in a wall bounding the cassette handling space, wherein the cassette handler is configured to additionally transfer wafer cassettes to and from the at least one cassette in-out port.
 18. The vertical batch furnace assembly according to claim 12, wherein for each wafer transfer opening the vertical batch furnace assembly comprises: a cassette door opener device configured to open a cassette door of a wafer cassette which has been placed in the wafer transfer position.
 19. The vertical batch furnace assembly according claim 12, wherein both the first and second cassette handler arms comprise a cassette gripper configured to grip a wafer cassette.
 20. The vertical batch furnace assembly according to claim 12, wherein the wafer cassettes are embodied as Front Opening Unified Pods (FOUP's). 